Concrete block assembly

ABSTRACT

A concrete block assembly for use in a septic tank sewage disposal system including a plurality of porous blocks each having multiple apertures therethrough oriented in end-to-end, sealed relationship and retained in this relationship by tension rods extending through the assembly to form a module which can be assembled at a factory site, transported to the site of installation and lowered into a trench or ditch to form part of the drain field of a septic tank disposal system. Connecting assemblies are provided for assembling a plurality of block modules in end-to-end communicating relationship to provide adequate capacity for each installation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to septic tank sewage disposalsystems and more particularly the drain field by which an effluent isdisposed of below ground surface in a well known manner with theinvention more particularly relating to an assembly of porous concreteblocks having tension rods extending through and connecting a group ofblocks into a module to facilitate assembly and installation of theseptic tank disposal system.

2. Description of the Prior Art

Septic tank sewage disposal systems basically include a septic tank anda drain field which includes a series of trenches or ditches dug intothe soil at a predetermined depth, a quantity of gravel, sand or thelike in the bottom of the trenches and drain tile disposed therein andcommunicated with the septic tank. The drain tiles are, in someinstances, spaced apart slightly to form discharge slots for liquideffluent so that such effluent will discharge into the soil surface. Oneof the problems which occurs in this type of installation is theincapability of the soil to absorb effluent and clogging of the drainfield by solid organic material. Most localities require that the soilpass a percolation test before a septic tank sewage disposal system canbe installed.

Efforts have been made to improve such systems with U.S. Pat. No.3,422,010 issued Jan. 14, 1969, disclosing a different type ofarrangement in which a plurality of concrete blocks of porous materialare assembled in sealed end-to-end relation by use of mortar with eachof the blocks including multiple passageways therein which, whenaligned, provide a drain field in which effluent is discharged throughthe blocks throughout the length of the drain field and throughout theperiphery of the blocks due to the multiple passageways therethrough inwhich the effluent will pass back and forth through the aligned blocks.

When installing this type of system, it is difficult to apply mortar tothe ends of the blocks and orient the blocks in end-to-end alignedrelation when at the bottom of a relatively narrow trench. In additionto being quite time consuming, the installation requires considerableexpertise and requires substantial manual handling and manipulation ofthe blocks, all of which render the installation of this type of blockrelatively inefficient and quite costly.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a concrete blockassembly for use in a septic tank drain field in which the concreteblocks are porous and provided with four relatively large openingsextending therethrough and tension members extending through a pluralityof blocks for maintaining them in assembled, end-to-end, alignedcondition with a mastic type cement between adjacent blocks so that theblocks may be assembled into a module at a factory site, transported tothe installation site and lowered into the drain field trench at theinstallation site thereby materially reducing the time and labor ininstalling a drain field and providing a drain field which is lesssubject to breakage or misalignment due to shifting soil, heavy trafficloads and the like.

Another object of the invention is to provide a concrete block assemblyin accordance with the preceding object in which the modules orassemblies may be interconnected in end-to-end relationship by speciallyconstructed clips and bolts to enable the modules to be easily assembledin the drain field ditch or trench so that the overall length andcapacity of the drain field may be varied to meet the requirements ofeach installation.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one of the porous concrete blocks.

FIG. 2 is a perspective view of the concrete block assembly or module inwhich a plurality of blocks illustrated in FIG. 1 are retained inassembled, end-to-end, sealed, aligned relation by tension rods.

FIG. 3 is a longitudinal, vertical sectional view taken substantiallyupon a plane passing along section line 3--3 of FIG. 2 illustrating thestructure of the tension rods and their relationship to the blocks.

FIG, 4 is a side elevational view of the end portions of two connectedassemblies or modules.

FIG. 5 is a longitudinal, vertical sectional view taken substantiallyupon a plane passing along section line 5--5 of FIG. 4 illustrating thespecific structural details of the connecting clips between adjacentassemblies or modules.

FIG. 6 is a perspective view of one of the connecting clips.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The porous concrete blocks 10 are constructed in a manner quite similarto that illustrated in U.S. Pat. No. 3,422,010, and includes flat sidewalls 12 defining a generally square block having planar end walls 14which are interconnected by four relatively large openings 16 extendingtherethrough. The blocks 10 are assembled in end-to-end relation and atthe end of each drain line or drain bed in the drain field, connectingelbows or end blocks with connecting passageways are employed so thateffluent will pass longitudinally in one of the passageways formed bythe aligned openings 16 until it reaches the end of the drain bed atwhich point it will reverse its flow and flow back through anotherpassageway formed by the openings 16 and thus, the effluent will passthrough the drain blocks four times all as disclosed in theaforementioned patent. In the aforementioned patent, the blocks 10 areindividually installed in relation to each other by using conventionalmortar so that each individual block is installed generally in theconventional manner of laying concrete blocks and the like.

In the present invention, each concrete block is provided with foursmall apertures 18 extending from end-to-end through the block. Theseapertures 18, when aligned, receive tension rods 20 therethrough withthe ends of the tension rods 20 having a threaded portion 22 receiving aretaining nut 24 thereon. Thus, by aligning a plurality of blocks 10 andinserting tension rods 22 therethrough and assembling clamp nuts 24 onthe ends of the rods 22, a plurality of blocks 10 may be assembled intoan assembly or module having a predetermined number of blocks with theassembly or module being illustrated in FIG. 2 and generally designatedby numeral 26. Disposed between adjacent blocks 10 in the assembly 26 isa sealing material 28 in the form of a mastic of a waterproof type whichmaintains a degree of resilience and flexibility for a relatively longperiod of time. The mastic 28 is applied to the end of the block, andthe blocks oriented in aligned relation and the tension rods assembledtherewith and the clamp nuts assembled with the tension rods to form theassembly or module at a factory site, so that the assembly or module maybe loaded onto a suitable truck, conveyed to the installation site andremoved from the truck body and lowered into the drain field ditch by asuitable hoist which may be attached to the truck body or may be aseparate piece of equipment. This procedure completely eliminates thenecessity of a skilled block layer individually applying mortar to eachblock and assembling these blocks at the bottom of the ditch or trenchand the tension rods prevent misalignment of the blocks and assure thatthey are all properly positioned and also retain such alignment eventhough the drain field may be subject to earth shifting or relativelyheavy traffic, such as trucks or the like, at ground level.

Each end face 14 of each block 10 includes recesses 30 in the opposededges thereof with the inner end of each recess 30 extending inwardlybeyond the aperture 18. The other two apertures 18 in the block 10 havethe terminal ends thereof surrounded by a recess or counterbore 32 sothat retaining nuts 24 will be received in either the counterbore 32 ornotch-type recess 30 with the end of the tension rods 20 and the nuts 24terminating either inwardly or substantially flush with the end surface14 of the block which forms the end block on the module 26. The purposeof the recess 30 is to receive a leg of a Z-shaped clip 34 which hasoppositely extending apertured end flanges or end portions 36 with theapertures therein being of a size to receive the tension rod 20. TheZ-shaped clips 34 are for the purpose of connecting two assemblies ormodules 26 in end-to-end relationship as illustrated in FIGS. 4 and 5with one of the apertured flanges 36 inserted into the recess 30 on theinner face of the endmost block 10 in the module as illustrated in FIG.5 with the aperture being received on the tension rod 20. The other legor flange of the clip 34 extends laterally outwardly in alignment withthe outer face of the endmost block 10 in the module as illustrated inFIG. 5. Thus, by using two of the Z-shaped clips 34 in the mannerillustrated in FIGS. 4 and 5 and by using a bolt assembly 38 to connectthe outwardly projecting flanges or legs together two adjacent modulesor assemblies 26 may be rigidly interconnected with each other and inalignment with each other with mastic 28 being disposed between thefacing surfaces of the endmost blocks on the adjacent modules orassemblies. While each block is provided with recesses 30, such recessis used only when the connecting clips are used and the recesses on theinner face of the endmost block are the only ones used but thisconstruction enables each of the blocks to be identically constructedthereby eliminating the necessity of having special end blocks. Also,the symmetrical location of the apertures 18 enables more rapid assemblyof the blocks since the person assembling the blocks only has to locatethe recesses 30 so that they are in the vertical side edges of theblocks when assembled. Thus, each block includes not only the recesses30 in each face thereof but also the counterbores 32 in each facethereof. This enables the mastic to be machine placed on the blocks notonly around the periphery thereof but also between the openings with themastic filling the unused recesses 30 and counterbore 32 so that theblocks 10 are sealed in relation to each other and the large openings 16are also sealed and isolated from each other. It is only necessary touse three tie rods 20 although four can be used if desired. The threetie rods provide adequate tensile force to maintain the blocksassembled. While fasteners 38 are in the form of bolts and nuts, othertypes of readily assembled fasteners may be used with it being pointedout that the flanges 36 project only slightly outwardly from the drainfield thereby enabling assembly of the modules in the drain fieldtrench. Each module may have a predetermined number of blocks thereinand by varying the number of modules, the overall capacity of a drainfield may be varied depending upon the installation or requirements.After the drain field has been prepared with appropriate ditches and adrain bed of gravel or the like if desired, the module or modules areinstalled and communicated with the septic tank system in a conventionaland well known manner, so that one of the passageways formed by thealigned openings is in communication with the discharge of the septictank system.

When installing the septic tank sewage disposal system, after the drainfield trench or trenches have been formed with the bottoms thereof beingsubstantially level, if only a single module of blocks is necessary, themodule may be either lowered into the trench and connected to the septictank and provided with appropriate elbows at each end interconnectingthe passageways or an appropriate end block at each end which connectsthe passageways. If multiple modules are necessary, a mastic is placedon the end of one module and two Z shaped clips utilized to connect themodules together. This not only enables the individual blocks in themodule to be more readily assembled at the factory site but alsofacilitates connection of multiple modules together at the installationsite, thus materially reducing the labor and time required in installingthe drain field in a septic tank sewage disposal system and providing adrain field which will be much more stable even though lateral pressuresmay be exerted when backfilling the trenches with loose soil or the likeand even though pressures may be exerted thereon by truck traffic or thelike traversing the ground surface thereby providing a longer lastingand more effective drain field which is less subject to clogging andalso less subject to inefficient operation due to misalignment orseparation of the blocks which sometimes occurs due to the deteriorationof the motor joints between adjacent blocks.

The blocks 10 are constructed with a lightweight aggregate which differsfrom regular concrete in that the weight of the blocks is substantiallyreduced and the porosity is materially increased. The lightweightaggregate is in the form of shale rapidly heated to a high temperatureand, in effect, exploded which forms small capillary passagewaystherethrough which occur throughout the completed block thus increasingthe porosity of the block.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:
 1. A concrete block drain lineforming a drain field of a septic tank sewage disposal system comprisinga plurality of identical porous concrete blocks oriented in end-to-endaligned and sealed relation, each block including a plurality of largeropenings extending therethrough to form a plurality of longitudinalpassageways for effluent flow and adapted to be interconnected at theirends, and tension means extending through small openings in theplurality of blocks for retaining the blocks in assembled sealedrelation prior to installation in the drain field, said small openingsbeing disposed symmetrically about the center of the blocks and betweensaid large openings and adjacent the periphery of the block, saidtension means being in the form of a plurality of tension rods extendingthrough the small openings in each block with retaining nuts on each endof each rod, the ends of the rod and retaining nuts being received inrecesses in the endmost blocks to enable adjacent, aligned assemblies tobe disposed in adjacent relation for interconnection, said blocks beingof square configuration with the large openings therethrough and smallopenings therethrough being symmetrically arranged to align the openingsin different positions of the blocks relative to each other, saidconcrete block drain line being in the form of a module to be orientedin end-to-end, aligned relation to similar modules to form a drainfield, and connecting means associated with the endmost blocks on saidconcrete block module, said connecting means including a recess inopposite side edges of the axially innerface of the endmost blocks ofthe concrete block module and retaining clips each having a portionreceived in the recess and on the tension rod and a portion extendinglaterally beyond the concrete block module with the projecting portionadapted to receive clamping bolts for securing the adjacent endmostblocks of two aligned concrete block modules in secure connectedrelation, each of said blocks in the concrete block drain line includingrecesses in both faces thereof to enable any of the blocks to beoriented as the endmost blocks and with either face of such blocks facedaxially inwardly of the concrete block module.
 2. The structure asdefined in claim 1 wherein each of said clips is Z-shaped and includesan inwardly extending leg inserted between the endmost adjacent blocksin each module and an outwardly projecting leg generally in alignmentwith the end face of each module, said clamping bolts extending betweenthe outwardly extending legs for connecting them together and retainingthe modules in aligned position.